2161530 has 96 divisors (see below), whose sum is σ = 6649344. Its totient is φ = 476928.

The previous prime is 2161513. The next prime is 2161553. The reversal of 2161530 is 351612.

2161530 = 48² + 49² + ... + 187².

2161530 is a `hidden beast` number, since 21 + 615 + 30 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 29574 + ... + 29646.

It is an arithmetic number, because the mean of its divisors is an integer number (69264).

2^2161530 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2161530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3324672).

2161530 is an abundant number, since it is smaller than the sum of its proper divisors (4487814).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2161530 is a wasteful number, since it uses less digits than its factorization.

2161530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 2161530 is about 1470.2142700981. The cubic root of 2161530 is about 129.2965953565.

The spelling of 2161530 in words is "two million, one hundred sixty-one thousand, five hundred thirty".